This is my issue with Wireguard. It is not good a firewall traversal. On restrictive nets really you have to get out via TLS port 443. No other way often works. So for the traveler OpenVPN TCP option can be way better. Nice to see Proton has a solution.

The other problem with Wireguard is that it is not necessarily as anonymous. The good VPN providers had to do special things to make that so.

Other then that, Wireguard is wonderful in terms of performance and presumably security too.